5.Eric Bana and Orlando Bloom as the princes of Troy in Troy: Here's my pick for the most uncanny casting when it comes to physical resemblance. While much of the cheesy spectacle of Troy defies any type of storytelling logic, the one thing you will believe in this movie is that Orlando Bloom's Paris really is the wimpy, foolish baby brother of Eric Bana's sensible, heroic Hector. And the next time you find yourself getting annoyed at having to bail your little brother out of a jam, this movie will put things in perspective for you. No matter what your brother's done, at least he never stole the wife of the king of Sparta, or forced you into a fight to the death with Hercules.

4.Edward Norton and Edward Furlong as the Vinyard brothers in American History X: This movie really explores the idea of what it means to be your brother's keeper. When a stint in jail causes Neo-Nazi Edward Norton to finally move past the hate that's been the driving force in his life, he takes up another cause -- to keep his younger brother from following in his footsteps. The differences in physical appearance between the two actors actually lends credibility to the portrayal of their relationship. You can see the pains Furlong's character goes to in his efforts to emulate the older brother he looks up to, and the torture it causes Norton to see himself reflected in his brother's eyes.

3.Owen Wilson, Adrien Brody, and Jason Schwartzman as the Whitman brothers in The Darjeeling Limited: We're so used to seeing Owen Wilson appear onscreen alongside at least one of his real-life brothers that it seemed impossible for him to try to re-create that chemistry with Brody and Schwartzman. But these three diverse actors were both heartbreakingly and hilariously accurate in how they captured the complex relationship between Jack, Peter, and Francis Whitman, three relative strangers travelling on a train through India together, wondering if they'd be friends if they'd ever known each other "not as brothers, but as people." From the way eldest brother Francis (Wilson) hates the way middle brother Peter (Brody) smugly declares himself their dead father's favorite, to little brother Jack's (Schwartzman) constant refrain of "stop including me!," any family will see a bit of themselves in this movie.

2.Tom Cruise and Dustin Hoffman as the Babbitt brothers in Rain Man: It's a common cinematic device for a story to be set in motion when a character meets a brother he never had. That's what happens to Charlie Babbit (Cruise) when his father's will leads him to his autistic older brother Raymond (Hoffman) -- the sole benefactor of their father's $3 million fortune. Seeing his brother as an easy pawn in a money-making scheme, Charlie kidnaps Raymond and naturally ends up learning valuable life lessons on their road trip adventure. By the end of the movie, Charlie accepts Raymond as family -- something the audience was able to accept them as all along.

1.Dan Aykroyd and John Belushi as Jake and Elwood Blues in The Blues Brothers: Some brothers share everything. For Jake and Elwood Blues, that involves a snazzy wardrobe, a penchant for getting in trouble, and killer taste in music. The Blues Brothers may be a little codependent, but they also prove that brothers can be soul mates, and make us all wish for a sibling who would always be happy to serve as a partner in crime.